Módulo:Color contrast
-- Thanks to Wikipedia for the source code -- This module implements -- -- -- -- -- local p = {} local HTMLcolor = mw.loadData( 'Module:Color contrast/colors' ) local function sRGB (v) if (v <= 0.03928) then v = v / 12.92 else v = math.pow((v+0.055)/1.055, 2.4) end return v end local function rgbdec2lum(R, G, B) if ( 0 <= R and R < 256 and 0 <= G and G < 256 and 0 <= B and B < 256 ) then return 0.2126 * sRGB(R/255) + 0.7152 * sRGB(G/255) + 0.0722 * sRGB(B/255) else return '' end end local function hsl2lum(h, s, l) if ( 0 <= h and h < 360 and 0 <= s and s <= 1 and 0 <= l and l <= 1 ) then local c = (1 - math.abs(2*l - 1))*s local x = c*(1 - math.abs( math.fmod(h/60, 2) - 1) ) local m = l - c/2 local r, g, b = m, m, m if( 0 <= h and h < 60 ) then r = r + c g = g + x elseif( 60 <= h and h < 120 ) then r = r + x g = g + c elseif( 120 <= h and h < 180 ) then g = g + c b = b + x elseif( 180 <= h and h < 240 ) then g = g + x b = b + c elseif( 240 <= h and h < 300 ) then r = r + x b = b + c elseif( 300 <= h and h < 360 ) then r = r + c b = b + x end return rgbdec2lum(255*r, 255*g, 255*b) else return '' end end local function color2lum© if (c nil) then return '' end -- html '#' entity c = c:gsub("#", "#") -- whitespace c = c:match( '^%s*(.-)%s;*$' ) -- unstrip nowiki strip markers c = mw.text.unstripNoWiki© -- lowercase c = c:lower() -- first try to look it up local L = HTMLcolorc if (L ~= nil) then return L end -- convert from hsl if mw.ustring.match(c,'^hsl%(%s*0-90-9%.*%s*,%s*0-90-9%.*%%%s*,%s*0-90-9%.*%%%s*%)$') then local h, s, l = mw.ustring.match(c,'^hsl%(%s*(0-90-9%.*)%s*,%s*(0-90-9%.*)%%%s*,%s*(0-90-9%.*)%%%s*%)$') return hsl2lum(tonumber(h), tonumber(s)/100, tonumber(l)/100) end -- convert from rgb if mw.ustring.match(c,'^rgb%(%s*0-90-9*%s*,%s*0-90-9*%s*,%s*0-90-9*%s*%)$') then local R, G, B = mw.ustring.match(c,'^rgb%(%s*(0-90-9*)%s*,%s*(0-90-9*)%s*,%s*(0-90-9*)%s*%)$') return rgbdec2lum(tonumber®, tonumber(G), tonumber(B)) end -- convert from rgb percent if mw.ustring.match(c,'^rgb%(%s*0-90-9%.*%%%s*,%s*0-90-9%.*%%%s*,%s*0-90-9%.*%%%s*%)$') then local R, G, B = mw.ustring.match(c,'^rgb%(%s*(0-90-9%.*)%%%s*,%s*(0-90-9%.*)%%%s*,%s*(0-90-9%.*)%%%s*%)$') return rgbdec2lum(255*tonumber®/100, 255*tonumber(G)/100, 255*tonumber(B)/100) end -- remove leading # (if there is one) and whitespace c = mw.ustring.match(c, '^%s#*(a-f0-9*)%s*$') -- split into rgb local cs = mw.text.split(c or '', '') if( #cs 6 ) then local R = 16*tonumber('0x' .. cs1) + tonumber('0x' .. cs2) local G = 16*tonumber('0x' .. cs3) + tonumber('0x' .. cs4) local B = 16*tonumber('0x' .. cs5) + tonumber('0x' .. cs6) return rgbdec2lum(R, G, B) elseif ( #cs 3 ) then local R = 16*tonumber('0x' .. cs1) + tonumber('0x' .. cs1) local G = 16*tonumber('0x' .. cs2) + tonumber('0x' .. cs2) local B = 16*tonumber('0x' .. cs3) + tonumber('0x' .. cs3) return rgbdec2lum(R, G, B) end -- failure, return blank return '' end -- This exports the function for use in other modules. -- The colour is passed as a string. function p._lum(color) return color2lum(color) end function p._greatercontrast(args) local bias = tonumber(args'bias' or '0') or 0 local css = (args'css' and args'css' ~= '') and true or false local v1 = color2lum(args1 or '') local c2 = args2 or '#FFFFFF' local v2 = color2lum(c2) local c3 = args3 or '#000000' local v3 = color2lum(c3) local ratio1 = -1; local ratio2 = -1; if (type(v1) 'number' and type(v2) 'number') then ratio1 = (v2 + 0.05)/(v1 + 0.05) ratio1 = (ratio1 < 1) and 1/ratio1 or ratio1 end if (type(v1) 'number' and type(v3) 'number') then ratio2 = (v3 + 0.05)/(v1 + 0.05) ratio2 = (ratio2 < 1) and 1/ratio2 or ratio2 end if css then local c1 = args1 or '' if mw.ustring.match(c1, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') or mw.ustring.match(c1, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') then c1 = '#' .. c1 end if mw.ustring.match(c2, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') or mw.ustring.match(c2, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') then c2 = '#' .. c2 end if mw.ustring.match(v3, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') or mw.ustring.match(v3, '^A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9A-Fa-f0-9$') then c3 = '#' .. c3 end return 'background-color:' .. c1 .. '; color:' .. ((ratio1 > 0) and (ratio2 > 0) and ((ratio1 + bias > ratio2) and c2 or c3) or '') .. ';' end return (ratio1 > 0) and (ratio2 > 0) and ((ratio1 + bias > ratio2) and c2 or c3) or '' end function p._ratio(args) local v1 = color2lum(args1) local v2 = color2lum(args2) if (type(v1) 'number' and type(v2) 'number') then -- v1 should be the brighter of the two. if v2 > v1 then v1, v2 = v2, v1 end return (v1 + 0.05)/(v2 + 0.05) else return args'error' or '?' end end function p._styleratio(args) local style = (args1 or ''):lower() local bg, fg = 'white', 'black' local lum_bg, lum_fg = 1, 0 if args2 then local lum = color2lum(args2) if lum ~= '' then bg, lum_bg = args2, lum end end if args3 then local lum = color2lum(args3) if lum ~= '' then fg, lum_fg = args3, lum end end local slist = mw.text.split(mw.ustring.gsub(mw.ustring.gsub(style or '', '&#Xx23;', '#'), '#', '#'), ';') for k = 1,#slist do local s = slistk local k,v = s:match( '^%s*(^:-):(^:-)%s;*$' ) k = k or '' v = v or '' if (k:match('^%s*(background)%s*$') or k:match('^%s*(background%-color)%s*$')) then local lum = color2lum(v) if( lum ~= '' ) then bg, lum_bg = v, lum end elseif (k:match('^%s*(color)%s*$')) then local lum = color2lum(v) if( lum ~= '' ) then bg, lum_fg = v, lum end end end if lum_bg > lum_fg then return (lum_bg + 0.05)/(lum_fg + 0.05) else return (lum_fg + 0.05)/(lum_bg + 0.05) end end --somecolor}} directly or from a wrapper template. Parameters: -- |1= — required; A color to check. -- function p.lum(frame) local color = frame.args1 or frame:getParent().args1 return p._lum(color) end function p.ratio(frame) local args = frame.args1 and frame.args or frame:getParent().args return p._ratio(args) end function p.styleratio(frame) local args = frame.args1 and frame.args or frame:getParent().args return p._styleratio(args) end function p.greatercontrast(frame) local args = frame.args1 and frame.args or frame:getParent().args return p._greatercontrast(args) end return p